High Rise Buildings Built with Denotators?

[megmo1571]

I've heard that high rise buildings are often built with denonators in them so that the building can be demolished in an emergency without it falling on other buildings and killing more people. Is this true and could this have happened on 9/11?

[scienceplease 2]

No, I don't think this is true.

The safety precautions needed to stop "accidental" detonation would be enormous.
On aircraft, all safety systems are well publicized.
Explosive devices need regular maintenance
AE911Truth members would have mentioned this if there was any truth to the matter.

This didn't happen on 9/11. The physics is pretty clear: it was controlled demolition for 1, 2 and 7. Novel military explosives were used. The detonators were most likely wireless. The devices to bring down the towers and WTC7 (and explosions in WTC 5 and 6) must have been installed during building renovation: for example, the elevator upgrade in the twin towers, "the largest ever" such upgrade. Or the "fire-proofing upgrades" in the areas where the building were impacted. Or Scott Forbes - a WTC witness of power-downs, preceding the attack (I wish there was better verification of that story). Explosive sniffer dogs were retired from patrolling the WTC a week before 9/11 according to 9/11 Mysteries, perhaps indicating that traditional RDX explosives may have also been used and installed in the weekend before 9/11.